Improvement in the art of autographic printing



UNITED STATES PATENT QFFIoE.

WILLIAM T. HOY VARD, OF BALTIMORE, MARYLAND.

IMPROVEMENT IN THE ART OF AUTOGRAPHIC PRINTING.

Specification forming part of Letters Patent No. 215,926, dated May 27,1879; application filed February 15, 1879.

To all whom it may concern:

Be it known that I, WILLIAM T. HOWARD, of the city of Baltimore, in theState of Maryland, have invented an Improvement in PreparingAutographic-Printing Plates, together with an improvement in the art ofautographic printing, in which the use of said plate is involved, ofwhich invention the following is a full, clear, and exact description.

This invention is founded on the known fact that a mercurial surfacewill resist or repel printers ink. I am aware that heretofore inventionsin printing and analogous arts have been made in which this fact hasbeen availed of but in one class of such inventions, wherein unengravedplates have been used, the galvanic battery has been called intorequisition in thepreparation of the printing-surface of the plates,while in the other class engraved plates, which it is the object of myinvention to avoid, have been used.

The plates used in these inventions have, as far as I have beeninformed, been made in two ways. In the first mode silver has beendeposited by galvanic action on a copper plate, as

a medium to promote a union between the said plate and a coating ofmercury. In the second mode the engraved plates, after the engravedlines have been filled with wax or other substance, have been rubbedwith metallic mercury. The first class of such inventions are unsuitablefor use in the hands of persons unskilled in electroplating, while thesecond class involve, as above stated, the use of an engraved plate,which cannot be applied to the purposes for which my invention isdesigned.

The simplicity of my improvements adapts them to the general uses ofmerchants, professional men, and subordinates in countingrooms, asindeed all to whom the rapid, cheap, and exact reproduction ofmanuscript is of value.

Hy invention relates, first, to providing an unengraved printing-plate,having an inked inscription thereon, with a mercurial surface withoutthe use of electrical apparatus, and without the necessity of rubbingthe mercury on said plate, which would obliterate or deface the inkedinscription. In carrying out this part of my invention, I take anordinary copper plate and transfer thereto from a paper written in inkthe writing or inscription to be reproduced in print, and then apply to,thc printing-surface of the plate one or more of the salts of mercuryin solution, whereby an amalgamated or ink-resisting coating is given tothe uninscribed portion of said plate.

The invention relates, secondly, to the process of autographic printing,in which the preparation and use of the above-described plate areinvolved. I carry out the process as an entirety as follows: I write orotherwise inscribe in transfer-ink, on paper, the desired writing orinscription to be reproduced in print 5 then transfer the same inreverse to an ordinary copper plate by pressure; then remove thetransfersheet; then apply, by immersion or a saturated pad or brush, tothe surface of the plate bearing the inked design one or more of thesalts of mercury in solution, to form a mercurial or amalgamated coatingto the uninscribed portion of said plate, then dry the plate and burnishit; then pour upon the amalgamated coating a small quantity of metallicmercury, which is diffused over the surface of the plate; and finallyroll it up in ink, and print therefrom after the manner of lithography.

It is obvious that the same effect may be obtained by writing thesubject to be printed in reverse with ink on the plate before treatingit with the mercurial solution; but it is equally apparent that greatinconvenience would arise therefrom to persons unskilled in the art ofcngravin g or etching.

I am aware that it is uotnew to coat metals with mercury by means of asolution of the salts of mercury 5 but I am not aware that an unengravedink-inscribed plate has been thus treated with the view of obtaining aprintingsurface, or with any other view whatsoever.

Having described my invention, I claim as new and wish to secure byLetters Patent of the United States 1. The within-described mode ofpreparing an autographic-printing plate, consisting in transferringthereto from a paper written in suitable ink, the writing or inscriptionto be reproduced in print, and then applying to the inked surface ofsaid plate one or more of the salts of mercury in solution, whereby anamalgamated or ink-resisting coating is given to removing thetransier-sheet, then applying to p the surface of the plate bearing theinked design one or more of the salts of mercury in solution, to form amercurial or amalgamated coating to the uninscribed portion of theplate,

then drying the plate and burnishin g it, then pouring upon'theamalgamated coating a small quantity of metallic mercury, and finallyrolling up the plate in ink and printing therefrom, substantially as setforth.

In testimony whereof I have hereunto subscribed my name this 14th day ofFebruary,

WILLIAM THOMPSON HOWARD.

Witnesses:

WM. 0. NIoHoLLs, JNo. S. MADDOX.

